Abstract

Damping is a significant dynamic characteristic used to describe rock vibration failures and plays an important role in various seismic engineering applications, specifically for evaluating stability of rock masses under forced vibration loading. In this paper, cyclic loading tests were carried out on sandstone and granite samples to study their damping characteristics. The effect of the selected influential indicators (stress level, strain amplitude and loading frequency) on the damping ratio and damping coefficient was studied. The damping parameters of sandstone and granite were calculated and the variability in the damping parameters as a function of stress level, frequency and strain amplitude were determined. The linear relationship between damping ratio, damping coefficient and strain amplitude was investigated. The results suggest that the relationship between the damping parameters and the strain amplitude could be expressed as a linear function. The influential indicators to the damping parameter of granite were sorted as follows: stress level > strain amplitude > frequency. The influential indicators of sandstone were sorted as follows: strain amplitude > stress level > frequency. Under a fixed-amplitude stress path, the damping ratio of granite was approximately 80% that of the sandstone and the damping coefficient is approximately 200% of that of the sandstone.

摘要

阻尼是用于描述岩石振动破坏的重要动态特性，在各种地震工程应用中发挥着重要作用，特别是用于评估强迫振动载荷下岩体的稳定性。本文对砂岩和花岗岩样品进行循环加载试验，研究其阻尼特性。研究了选定的影响指标（应力水平、应变幅值和加载频率）对阻尼比和阻尼系数的影响。计算了砂岩和花岗岩的阻尼参数，并确定了阻尼参数随应力水平、频率和应变幅度的变化。研究了阻尼比、阻尼系数和应变幅值之间的线性关系。结果表明，阻尼参数与应变幅值之间的关系可以表示为线性函数。影响花岗岩阻尼参数的指标排序为：应力水平>应变幅值>频率。砂岩的影响指标排序为：应变幅值>应力水平>频率。在定幅应力路径下，花岗岩的阻尼比约为砂岩的80%，阻尼系数约为砂岩的200%。砂岩的影响指标排序为：应变幅值>应力水平>频率。在定幅应力路径下，花岗岩的阻尼比约为砂岩的80%，阻尼系数约为砂岩的200%。砂岩的影响指标排序为：应变幅值>应力水平>频率。在定幅应力路径下，花岗岩的阻尼比约为砂岩的80%，阻尼系数约为砂岩的200%。